For this Career Development Award application, I will capitalize and build on my past training experience which includes: a) a Master's Degree in Clinical Dietetics; b) experience as a Research Dietitian at the NIDDK in Phoenix, during which I investigated the relationship between food intake and energy metabolism; c) a Doctorate Degree from the University of Alabama at Birmingham, where my research focused on the use of 31p Magnetic Resonance (MR) Spectopscopy to measure skeletal muscle metabolism; and d) a Post-doctoral Fellowship at UAB where I used 1H MR Spectroscopic Imaging to look at the impact of dietary fat on intramyocellular lipid content. As part of my overall project "Impact of Diet on Intramyocellular Lipid, Endurance Performance and Insulin Sensitivity", I am proposing to learn research skills that will help complement my current knowledge/capabilities. These skills include the technologies for measuring: a) skeletal muscle lipid and glycogen content by biochemical and histochemical techniques; b) muscle fat infiltration by computed tomography; c) intracellular lipid content in liver using 1H MR spectroscopy; d) carbohydrate metabolism using 13C- MR spectroscopy; e) insulin sensitivity by the hyperinsulinemic euglycemic clamp; and f) lipid metabolism using stable isotope infusion. I will also increase my knowledge of basic exercise physiology techniques, clinical research administration and bioethics. My project involves three individual studies (projects) that have been peer reviewed and funded. Project 1 will address whether differences in the amount of fat stored within the skeletal muscle as a result of endurance exercise and either a very-low fat or moderate-fat diet will result in differences in endurance performance. Project 2 will focus on the influence of either a low-fat or a moderate fat diet on adaptation to 16-weeks of exercise training. Project 3 will test whether lipid content in skeletal muscle and liver correlates positively with abdominal subcutaneous adipocyte size in type 2 diabetics and obese non-diabetics, and negatively with insulin sensitivity. My involvement in these projects will provide the perfect opportunity to develop these research skills. To achieve my career development goals, I will be mentored by: Drs Eric Ravussin (Sponsor), Claude Bouchard, Donna H. Ryan, David E. Kelley, Gerald I. Shulman and Mark A.Tarnopolsky (consulting sponsors). Completion of this mentored training will position me to achieve my long-term career objective of becoming an independent investigator with expertise in energy and macronutrient metabolism. There is ample equipment and facilities at the Pennington Center to support the projects and career development plan proposed.